Transdisciplinary efforts build on stakeholders from diverse fields and backgrounds coming together in temporary groups to address sustainability-related, often wicked, challenges. Working in small groups towards a common goal ultimately raises the concern of group dynamics, and while previous research has shown that group dynamics are significant for the performance and creativity of small groups addressing complex issues, the topic of group dynamics is largely under-researched in relation to transdisciplinarity. Thus, to investigate the connection between group dynamics, performance, and creativity in transdisciplinary project groups, a theoretical framework was developed and applied to a transdisciplinary-oriented course at KTH Royal Institute of Technology in Stockholm, Sweden. Through ethnographic field research, this study evaluates the group dynamics, performance, and creativity levels of five student groups, and explores what facilitation techniques can be applied in groups to promote favorable group dynamics. The findings indicate a relationship between group dynamics, performance, and creativity, and suggests that group dynamics can in fact be influenced by group members or project facilitators for improved sustainability problem-solving. This study brings together theory from fields such as transdisciplinarity, project management, small group dynamics, and pedagogics in an innovative way, and the certain emphasis on group dynamics is what makes the perspective of this study unique and a valuable contribution to the fields of transdisciplinary and education for sustainable development (ESD). The theoretical framework developed in this study provides a comprehensive conceptualization of group dynamics aspects relevant for complex problem-solving, and could potentially be transferable for answering similar questions in other courses.